<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>定位机制</title>
    <style>

          .box{
                width: 200px;
                height: 200px;
                background-color: greenyellow;
                margin-top: 20px;

          }

          .move {
                position: absolute;
                left: 100px;
                top:50px
          }

          .container{
                /*position: relative;*/
                margin-left: 300px;
          }
    </style>
</head>
<body>

<div class="container">
    <div class="box">1</div>
    <div class="box move">2</div>
    <div class="box">3</div>
</div>



</body>
</html>